Directed navigation of rounds

ABSTRACT

The system and method of directed navigation using an augmented semi-active laser seeker to provide initial altitude measurement and command denotation information for rounds. Using on-board sensors and communications links between members of a swarm, numerous targets can be engaged more quickly and precisely. The LCSAL can act as 3D LIDAR where the LCSAL&#39;s spatial resolution and the associated image from the imager can be correlated to the LCSAL pixel by pixel as time of arrival. The rounds trajectory can be refined due to coupling with accurate Target ID to provide optimum command detonation for specific target types.

FIELD OF THE DISCLOSURE

The present disclosure relates to directed navigation and more particularly to using an augmented semi-active laser seeker to provide initial altitude measurement and command denotation information for rounds.

BACKGROUND OF THE DISCLOSURE

Current guided munitions systems generally have limited weight and space allocations for imagers, which reduces their ability to locate and identify targets such as to only 1 to 2 Km. Given these weapons are launched at targets from 3 to 20 Km away, the current seekers are generally insufficient to navigate to the target. When using a designator as a means for in-flight navigation of the projectile to the target, current systems typically designate for the entire flight for a single round or projectile. This approach is time consuming, limits the rounds based on the designator resources, and results in rounds potentially firing every minute sequentially. For example, if the targeting platform needs to fire 10 rounds for the engagement, it may take 10 minutes to fire the 10^(th) round. In a swarm boat situation, for example, it is desirable to fire 5 to 20 rounds is less than a minute in a rapid-fire sequence or at about 3 second intervals. This allows for the platform to dispense enough rounds and to move to another location and lessen risks to the platform. Any delays in firing increases the associated risks to equipment and personnel.

Wherefore it is an object of the present disclosure to overcome the above-mentioned shortcomings and drawbacks associated with the conventional object tracking and navigation systems.

SUMMARY OF THE DISCLOSURE

One aspect of the present disclosure is a system for swarm navigation, comprising: a plurality of rounds, wherein the plurality of rounds comprises a leader round and one or more follower rounds, each round comprising: a diode configured to: generate pulsed energy to illuminate a target area comprising multiple targets; provide a transmitter portion of a laser range finder altimeter function; provide a transmitter portion of a proximity sensor for determining range to the target area comprising multiple targets; and provide a transmitter portion for a 3D LIDAR function for target aim refinement by combing data from a SAL seeker imager; the SAL seeker being configured to: receive pulsed energy reflected from the target area; determine angular bearing information if a follower round of any rounds in front of it; and provide a receiver function via an optical communications link for messages from the plurality of rounds; an imager having a FOV, the imager being configured to: use a horizon to determine an up and down reference; collect images of the target area; and capture images of multiple targets within the target area; and a processor configure to: correlate received pulsed energy reflected from the target area via the SAL seeker with images of the scene captured by the imager to form 3D images of multiple targets within the target area; determine a data set comprising: time from launch and estimated time to go to the target area; a number of targets in the target area; a spacing for multiple targets within the target area; a target cross range dispersion; a range from the round to the multiple targets in the target area; the round's position relative to remaining plurality of rounds; the round's current altitude; which target the leader round is engaging; a selected target based on the round's control authority and its range or time to go to the selected target, after removing previously selected targets (if the round is a follower) from the total targets in the target area; and transmit the data set to remaining rounds in the plurality of rounds via a communication link.

One embodiment of the system for swarm navigation using a follow the forward approach further comprises additional components including one or more navigation sensors, and IMUs.

Another embodiment of the system for swarm navigation using a follow the forward approach further comprises a barometer to maintain altitude once calibrated by the laser altimeter. In some cases, the system for swarm navigation further comprises a deployment mechanism for deploying the sensor suite from a radial viewing mode to a forward looking mode for use as a proximity sensor during terminal guidance.

In certain embodiments, the system for swarm navigation further comprises using 3D images for target ID and command detonation for a target type. In certain cases, the system for swarm navigation using a follow the forward approach further comprises use of a designator.

Another aspect of the present disclosure is a method for swarm navigation, comprising: providing a plurality of rounds, wherein the plurality of rounds comprises a leader round and one or more follower rounds, each round comprising: generating pulsed energy, via a diode, to illuminate a target area comprising multiple targets; providing a transmitter portion of a laser range finder altimeter function, via the diode; providing a transmitter portion of a proximity sensor, via the diode, for determining range to the target area comprising multiple targets; providing a transmitter portion for a 3D LIDAR function, via the diode, for target aim refinement by combing data from a SAL seeker imager; receiving pulsed energy reflected from the target area, via the SAL seeker; determining angular bearing information, via the SAL seeker, if a follower round of any rounds in front of it; providing a receiver function via an optical communications link for messages from the plurality of rounds; using a horizon to determine an up and down reference via an imager having a FOV; collecting images of the target area, via the SAL seeker; capturing images of multiple targets within the target area, via the SAL seeker; correlating received pulsed energy reflected from the target area via the SAL seeker with images of the scene captured by the imager to form 3D images of multiple targets within the target area, via a processor; determining, via the processor, a data set comprising: time from launch and estimated time to go to the target area; a number of targets in the target area; a spacing for multiple targets within the target area; a target cross range dispersion; a range from the round to the multiple targets in the target area; the round's position relative to remaining plurality of rounds; the round's current altitude; which target the leader round is engaging; and a selected target based on the round's control authority and its range or time to go to the selected target, after removing previously selected targets (if the round is a follower) from the total targets in the target area; and transmitting the data set to remaining rounds in the plurality of rounds via a communication link.

One embodiment of the method for swarm navigation using a follow the forward approach further comprises providing additional components including one or more navigation sensors, and IMUs. In some cases, the method for swarm navigation using a follow the forward approach further comprises providing a barometer to maintain altitude once calibrated by the laser altimeter.

Another embodiment of the method further comprises deploying the sensor suite from a radial viewing mode to a forward looking mode for use as a proximity sensor during terminal guidance. In some cases, the method for swarm navigation using a follow the forward approach further comprises using 3D images for target ID and command detonation for a target type. In certain embodiments, the method for swarm navigation further comprises using a designator.

Another aspect of the present disclosure is a method for swarm navigation, comprising: providing a plurality of rounds, wherein the plurality of rounds comprises a leader round and one or more follower rounds, each round comprising: generating pulsed energy, via a diode, to illuminate a target area comprising multiple targets; providing a transmitter portion of a laser range finder altimeter function, via the diode; providing a transmitter portion of a proximity sensor, via the diode, for determining range to the target area comprising multiple targets; providing a transmitter portion for a 3D LIDAR function, via the diode, for target aim refinement by combing data from a SAL seeker imager; receiving pulsed energy reflected from the target area, via the SAL seeker; determining angular bearing information, via the SAL seeker, if a follower round of any rounds in front of it; providing a receiver function via an optical communications link for messages from the plurality of rounds; using a horizon to determine an up and down reference via an imager having a FOV; collecting images of the target area, via the SAL seeker; capturing images of multiple targets within the target area, via the SAL seeker; correlating received pulsed energy reflected from the target area via the SAL seeker with images of the scene captured by the imager to form 3D images of multiple targets within the target area, via a processor; determining, via the processor, a data set; and transmitting the data set to remaining rounds in the plurality of rounds via a communication link.

One embodiment of the method is wherein the data set comprises: a time from launch and estimated time to go to the target area; a number of targets in the target area; a spacing for multiple targets within the target area; a target cross range dispersion; a range from the round to the multiple targets in the target area; the round's position relative to remaining plurality of rounds; the round's current altitude; which target the leader round is engaging; and a selected target based on the round's control authority and its range or time to go to the selected target, after removing previously selected targets (if the round is a follower) from the total targets in the target area.

Another embodiment of the method further comprises providing additional components including one or more navigation sensors, and IMUs. In some cases, the method further comprises providing a barometer to maintain altitude once calibrated by the laser altimeter.

Yet another embodiment if the method for swarm navigation further comprises deploying the sensor suite from a radial viewing mode to a forward looking mode for use as a proximity sensor during terminal guidance. In certain embodiments, the method further comprises using 3D images for target ID and command detonation for a target type.

These aspects of the disclosure are not meant to be exclusive and other features, aspects, and advantages of the present disclosure will be readily apparent to those of ordinary skill in the art when read in conjunction with the following description, appended claims, and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages of the disclosure will be apparent from the following description of particular embodiments of the disclosure, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the disclosure.

FIG. 1 is a diagram of one embodiment of swarm navigation using an augmented semi-active laser seeker for altimeter and command detonation functions according to the principles of the present disclosure.

FIG. 2 is a diagram of one embodiment of swarm navigation using an augmented semi-active laser seeker for altimeter and command detonation functions according to the principles of the present disclosure.

FIG. 3 is a diagram of one embodiment of swarm navigation using an augmented semi-active laser seeker for altimeter and command detonation functions according to the principles of the present disclosure.

FIG. 4 is a diagram of one embodiment of a communications link used in object tracking and swarm navigation using an augmented semi-active laser seeker for altimeter and command detonation functions according to the principles of the present disclosure.

FIG. 5 is a diagram of another embodiment of swarm navigation using an augmented semi-active laser seeker for altimeter and command detonation functions according to the principles of the present disclosure.

FIG. 6 is a diagram of one embodiment of method of swarm navigation using an augmented semi-active laser seeker for altimeter and command detonation functions according to the principles of the present disclosure.

FIG. 7A and FIG. 7B are functional block diagrams of some processing steps illustrating data collection and computed navigation data in a cascade from a forward most round FIG. 7A to a following round FIG. 7B according to the principles of the present disclosure using an augmented semi-active laser seeker for altimeter and command detonation functions.

FIG. 8 is a diagram of another embodiment of swarm navigation using an augmented semi-active laser seeker for altimeter and command detonation functions according to the principles of the present disclosure.

FIG. 9 is a flowchart of one embodiment of a method according to the principles of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

One aspect of the present disclosure is a system comprising a plurality of rounds fired in a controlled sequence (weapons, missiles, guided rockets, free fall munitions, glide bombs, artillery, or the like) that act in concert. These rounds navigate to a plurality of targets using a forward most round's position relative to a target array. The forward most round is guided by a laser designator to engage a specific target within the target array. As the forward most round approaches the target array (multiple targets in a formation), an imager (LWIR, NIR, Visible, SWIR or MWIR) is used by the forward most round to characterize the array in terms of number of targets, relative position of each target to each other, classification/ID of the multiple targets, estimated target and forward most round range from the launch platform. In certain embodiments, the forward most round communicates this information back to the plurality of lagging munitions.

Certain embodiments of the system of the present disclosure comprise a rearward communications links (e.g., a 1 to 5 Hz rate) comprised of a coded laser/optical transmissions to provide all data gathered from a forward round to allow a next round in the sequence to determine which target it should select based on its range to target and control authority to ensure a high probability of hit. As the information is cascaded to each successive round, the transmitting round adds its target selection and its current location and altitude relative to the target formation allowing the following rounds to engage unselected targets and targets within their range.

A feature of the optical communications link is that each round has a SAL seeker, which can locates 1 to N rounds in its forward field of view (FOV). By knowing each forward round's trajectory and position within the trajectory, based on their target selections and coded communication messages, the ability of each round to navigate to an unselected target is done using an ad hoc, round constellation approach.

In one example, once the imager of the forward round acquires the target array, the use of a designator is no longer necessary and the plurality of rounds form a navigation network stretching from the launch platform to the target area. In one embodiment of the system, the rounds engage a land based threat. In this embodiment, the designator points to a ground position in the center of the target array. An imager on the round, such as the forward round, working with the semi-active laser seeker detects the laser return and correlates it to one or more pixels in the scene captured by the imager. That correlation allows the forward round to navigate to the ground position anointed by the laser using terrain navigation. To detect the plurality of targets, the round in one example needs to be closer to the target set given its limited optics. Once the target array has been detected, as described above, the forward round characterizes the engagement and provides the following rounds the necessary information for target selection and navigation to such target.

Augmenting a low cost semi-active laser seeker with a high powered laser diode to allow in one example the ability to function as an altimeter. For example, in one example the laser diode would be able to measure to about 2000 meters off the deck right after de-roll and prior to deployment of the sensor suite. In certain cases, the sensor suite is comprised of a low cost (LC) SAL (less than $1000), a high power laser diode (˜1000 watts—peak power) with beam forming optics. In a further example, a barometer is stowed in a radial view position. Once launched, and prior to the de-roll of the round, the laser diode activates and sends a series of pulses and the LCSAL receiver looks for a response from a ground direction such as in a 360 degree rotation pattern. From a typical helicopter launch (altitude 50 to 200 meters of the ground) as depicted in FIG. 2, the series of pulses' returns provides the direction of the ground/water and the distance. By knowing the distance the altitude or navigate altitude can be processed. In the scenario of a high altitude launch (about 10 to 30 K ft), as depicted in FIG. 1, the laser diode may not be of sufficient power (about 1000 watts peak power) to achieve a measurement from the ground or deck and the barometer provides an altitude reference.

After determining altitude, the sensor suite is rotated into a deployed position, i.e., looking forward. In the deployed position, the sensor suite in now employed as a proximity sensor as the round approaches the target. This allows the system to engage a target swarm or use pre-denotation prior to contact with the target for maximum warhead effects. Using an existing low cost semi-active laser (LCSAL), augmented with the high power diode (about 1000 watts), provides both an accurate azimuth/elevation (about 1 mrad) and target range, and a closure rate can be determined. This provides input into the round's terminal guidance processor for optimizing the rounds position (e.g., <1 meter) relative to the target.

In certain embodiments, the LCSAL receiver is responsible for receiving proximity information to the target swarm, communications from rounds in its forward view, and designator reflections from the targets deployed in the particular engagement. In one example, the series of pulses from the rearward facing high power laser diode for each round can be managed with time separation, or the like to distinguish the rounds. The designator, if present, is on a predetermined time schedule known to the round(s) inflight (typically a pulse at a 20 Hz rate). In one example, the communications between the rounds is an ad-hoc network with a leader-flower approach. The leader round would set a time relative update rate (such as 1 Hz) and then the follower(s) would cascade the communications messaging accordingly. For example, a 200 BIT message containing current positon, target grouping/dispersion information, target selection and position in the rounds group would be relayed. The proximity ranging and sensor fusing would be local to each round with its unique code, e.g. PRI coding, to eliminate crosstalk among the rounds.

As an example to explain the communications processing, in one example a pulse density of 20 designator pulses per second is used to control the lead round for 20 pulsed/second. Coupled with a 200 pulse communications message produces 2000 pulses (200 messages*10 rounds) and proximity ranging at 20 Hz for each round for additional 2000 pulses/second (20 Hz*10 weapons). The last round in flight could potentially see 4200 pulses, where 20 are from a designator, 2000 are communications messages and 2000 are for command detonation. In some cases, each pulse occupies 20 nanoseconds, only 0.0084% of the time base is consumed (i.e. 1/(20 nanoseconds*the 4200 pulse count per second in % time). In this situation, the likelihood of crosstalk is remote (e.g., 2 pulses at the same time is only 0.0084% of the time or once per about every 3.3 hours) and PRI sorting methods can adequately decode the communications messages and update the navigation/guidance for the each of the rounds to within about <1 meter remaining to the target's location.

Referring to FIG. 1, a diagram of one embodiment of swarm navigation using an augmented low cost semi-active laser for altimeter and command detonation functions according to the principles of the present disclosure is shown. More specifically, as used herein a moving object that is part of a swarm may be a round or a UAS. As used herein, a round may be a round, a projectile, a ballistic, a bullet, a munition, a guided round, or the like. In certain embodiments, a guidance kit, such as a mid-body guidance kit on a round sees the location of previous rounds using a semi-active laser seeker, a communication link, and the like. For each member (e.g., round) the location is known, both range and location to target, as part of the approach described herein. In the early stages of the launch of a round the altimeter collect range data between the round and the ground/sea before deploying to a forward looking orientation.

Still referring to FIG. 1, a first round, or forward, 2, starts a volley with the designation of the one or more targets. A second round 4 uses the designator information and other information received 10 from the first round 2. Here, the second round 4 will adopt a trajectory 16 so that an efficient mission can be accomplished. A third round 6 uses the designator information and other information received 12 from the second round 4 and information received 10 from the first round 2 to determine its trajectory 18 according to the still available one or more targets. This process continues on to a fourth round 8 using the information received from the preceding rounds (14, 12, 10) to determine a trajectory 20 to effectively accomplish the mission. A final round follows the preceding other rounds to the target area. The use of a designator, in this example, can stop at the end of firing. In some cases, this allows for rapid firing of several rounds and uses communications links and location information to more effectively engage multiple targets such that time can be saved by having each round select an optimal target based on leader/follower information. It also provides for limited use of a designator, which can be helpful in clandestine missions. In one example, an optimal target might for a later fired round might require the round to turn and head towards a further target because the round has more time to go, requiring less Control Authority to reach the target, while an earlier fired target could pick a more proximal target since it would have depleted dispersion/control authority in comparison to a later fired round.

Referring to FIG. 2, a diagram of one embodiment of swarm navigation using an augmented semi-active laser seeker for altimeter and command detonation functions according to the principles of the present disclosure is shown. More specifically, one embodiment of the system 30 of the present disclosure has the ability to launch a canister of rounds (e.g., 19 rounds) using a singular designated target while engaging all approaching targets 48, e.g., Fast Attack Boats. In this embodiment, a designator is used to guide a leader round 32 to a center mass 42 of the incoming targets 48. The leader 32 is launched toward the target set 48. Prior to de-rolling, while coming out of the canister, a high power laser diode transmits a series of pulses to determine the direction and range to the water. This information coupled with a barometer allows the leader round 32 to maintain altitude to the ground using the barometer. The sensor suite on-board the round would then re-orientate into an attack position, i.e., looking forward. The leader round 32 would continue toward the target until an imager (e.g., LWIR imager) detects the swarm and selects a target using ATR, or the like. Once the terminal guidance control on the round is activated, the trajectory towards the target is selected to point the round directly at the selected target and the high power diode acts as a proximity sensor as the round approaches the selected target. The data from the imager provides Az/El bearing information while the proximity sensor provides range and closure rate information to the round relative to the selected target. In certain embodiments, a LCSAL can act as 3D LIDAR since the LCSAL offers 1-2 mrad spatial resolution and the associated image from the imager can be correlated to the LCSAL pixel by pixel as time of arrival. The rounds trajectory can be refined due to coupling with accurate Target ID to provide optimum command detonation for specific target type.

Still referring to FIG. 2, an EO/IR communications link, or the like, and a SAL seeker allow any following rounds 34, 36 to see where the previous rounds 32 are in their current flight path via 38, 40. By knowing their respective range to target and their position relative to the targets and each target's location (via a cascade of communications to the rounds in the rear) the swarm (32, 34, 36, collectively) can use the signal Az/El information as an inflight constellation to guide the plurality of rounds (32, 34, 36) to the targets (42, 44, 46). Each round selects a unique target in the cascade and applies the 3D LIDAR data with the imager's data for optimum command detonation for target type.

Current systems require 45 to 60 seconds per round to launch for a total of 1140 seconds (for 19 rounds). In contrast, the present disclosure provides for emptying a canister (of 19 rounds) in a single pass in <100 seconds. In one embodiment, it takes about 40 seconds to aim the first round, and each of the remaining 19 units are launched in 3 second intervals thereafter.

Referring to FIG. 3, a diagram of one embodiment of swarm navigation using an augmented low cost semi-active laser for altimeter functionality at launch (and maintenance of altitude using a barometer during the flight) as well as command detonation functions according to the principles of the present disclosure is shown. More specifically, a lead round 54 is launched via a platform 50 and that lead round 54 acts as a scout and reports several pieces of information back to the remaining members of the swarm. In one embodiment, the information reported by the leader to the followers includes the range to a target group 69, cross range spread 68, the number of targets (here, 4), the spacing of targets within the target group, and the like. This information is then used to map trajectories 54, 58, 62, 66 for the members of the swarm (52, 56, 60, 64) to each target in the target group 69, such as which target the leader is engaging, the position of the leader relative to the group, the leader's current altitude, and the like. The information reported by the second member 56 of the swarm includes an echo of the leader's information, the second round's range position relative to the group, which target the second round is engaging, and the like. The subsequent rounds 60, 64 echo the leader's information, report their respective range position relative to the group, which target they are engaging, and the like. By knowing the horizon, the altitudes of the members ahead, the range of the members ahead and the respective “time to go” to the target area, each lagging round can select the next target and map a trajectory, e.g., 54, 58, 62, 66, that results in a highest likelihood of engagement.

Referring to FIG. 4, a diagram of one embodiment of swarm navigation using an augmented low cost semi-active laser for altimeter and command detonation functions according to the principles of the present disclosure is shown. More specifically, one embodiment of the system provides the ability to communicate round to round in a cascade fashion from the leader (70) to the follower (74) using a SAL seeker as both a designator sensor and a communications link receiver. In one embodiment a round 70 has a high power laser diode (e.g., 1.5 μm) that radiates a 20 to 30 degree beam 72 and a following round 74 at around 300 to 600 meters behind the leader receives the information transmitted and can get a bearing of its position and a cascade message from the leader 72. In certain embodiments, the message contains: a range to a target group, a cross range target spread, the number of targets within the target group, the spacing of targets within the target group, and the like. All of this transmitted information is used to map trajectories for other members of the swarm, which target a particular round is engaging, a position for a round relative to the other members of the swarm, a current altitude for each round, and the like.

Current solutions tend to use RF, which requires an additional RF receiver component. In contrast, the low cost semi-active laser seeker of the present disclosure can provide both a designation function and a communications receiver function with the added benefit of determining a direction of arrival for signal from the transmitting round (located in front of a receiving round) thus allowing in flight navigation of the follower round using a follow the leader approach. In one embodiment, the seeker has a 20° to 30° FOV coverage, using a high power pulsed diode of about 100 watts, about a 500 nanosecond pulse, at about 5 to 10 KHz, and about a 200 bit message. The seeker can provide the range to target group, cross range spread, the number of targets, the spacing of targets within the group, all for use in mapping trajectories for the members of the swarm. This allows each member to message which target that member is engaging, its position relative to the group, and its current altitude, all at about a 2 to 5 Hz Bit rate. The low cost semi-active laser (LCSAL) seeker therefore can provide a designator location, a communications link, and /message and bearing information of the round in front of it.

Referring to FIG. 5, a diagram of another embodiment of swarm navigation using an augmented low cost semi-active laser for altimeter and command detonation functions according to the principles of the present disclosure is shown. In this application, the laser altimeter may not provide a range to ground due to the round being at increased altitude. The sensor suite would instead indicate no return information and inform the guidance control that the round is in a high altitude engagement. The sensor suite would then deploy in the forward looking position. More specifically, one embodiment of the system for swarm navigation using a follow the leader approach has the ability to fire a salvo of rounds against several ground based targets at long range. In one embodiment a laser designator 82 is used to mark a reference point on the ground 86 proximate the targets 84 and a reflected signal 85 that is detected by the low cost semi-active laser seeker on the round 88. Using a forward looking LWIR sensor on the leader round 88, an image of the ground 86 is taken by the LWIR imager and the designator reference is transferred to that image. The round 88 is then flown using image-based navigation until the LWIR sensor IDs the target for terminal guidance. A LWIR sensor with a small aperture can generally only detect to about to 1.5 Km, thereby needing longer periods of designation. In this embodiment, only 3 to 4 seconds are required rather than the 20 to 30 seconds of traditional systems, allowing the platform 80 to get out of harm's way much sooner. This also allows for use of a salvo of several rounds using the follow the leader approach for subsequent launches by anointing the track reference point on the ground, using the LWIR imagery for navigation until the sensor detects the target using the anointed reference point. This ability for the platform to break off and then have the attack happen can preserve resources. Additionally, using a follow the leader approach, multiple rounds can be expended in a single pass which saves time.

Referring to FIG. 6, a diagram of one embodiment of a method of swarm navigation using an augmented low cost semi-active laser for altimeter and command detonation functions according to the principles of the present disclosure is shown. More specifically, a diagram demonstrating how the data is collected, processed, and cascaded to follower rounds is shown. In one embodiment, a processor 90 on-board a round performs a variety of functions. For example, the at least one processor 90 determines a horizon, and up and down from imagery 92 collected by an imager 94. In some cases, the imager is an LWIR imager. The on-board processor 90 in one example correlates a laser spot reflection off a target 98 received via a SAL seeker 96 of a signal sent from a designator. The imagery with the image of the scene 92 captured by the imager 94 in one example is from the leader round. The leader round in one example navigates to the target using a designator until the target array is detected and is in close enough proximity for the high power laser diode to paint the target. At this point the designator can disengage and operate with another set of rounds or targets, if needed. The leader round uses the high power laser diode 108 to paint the target area and establish the Az/El position from the returned signal. The imager 94 captures imagery of the scene 92 and the on-board processor 90 processes the information data set from the leader round that is transmitted via the rearward facing communications system 104 such as via an electro-optical/infrared (EO/IR) transmitter to transmit the coded information 106. If the round is a follower, the on-board processor generates a navigation trajectory based on the leader(s) position relative to the target array and horizon based on data 102 received from a communications link 100 via the SAL seeker 96. The processor 90 in one example performs Automated Target Recognition (ATR), or the like, and determines the engagement data for the mission, including the number of targets, cross range dispersion, target IDs, etc. The on-board processor 90 selects a target based on that round's control authority and its range or time to go to the selected target, after removing previously selected targets (if the round is a follower) from the total targets of a group. Additionally, the on-board processor 90 forms a data packet 106 and broadcasts it via a communication link 104 to other rounds in order to sustain the cascade. In some cases, the on-board processor receives data from additional components, including a high power laser diode and beam forming optics system 108, an IMU 110 and a barometer 112.

Referring to FIG. 7A and FIG. 7B, functional block diagrams of some processing steps illustrating data collection and computed navigation data in a cascade from a forward most round FIG. 7A to a following round FIG. 7B according to the principles of the present disclosure are shown. More specifically, the block diagrams comprise each round's sensor suite with the elements/subsystems needed to collect the data and process the data to formulate the communications data packet that is used to communicate between members of the swarm.

Referring to FIG. 7A, the forward round 120 has a processor 122 that correlates the scenes for the SAL seeker 124 and imager 126, where the imager 126 has a FOV 132 and captures multiple targets 134 a . . . 134 n. The imager 126 collects images of the target scene and uses a horizon to determine an up and down reference. In some cases, the round has additional components 128 including one or more navigation sensors, IMUs, laser range finder altimeters, and the like. In some cases, a designator 136 is used to illuminate 138 a target area comprising multiple targets 134 a . . . 134 n and that feedback 140 is received by the SAL seeker 124. In one example, an on-board, high-power diode 108 illuminates 142 the target area comprising multiple targets 134 a . . . 134 n. The processor 122 determines range from the round to the target group, clocked time from launch and estimated time to go to the target area, target array cross range dispersion, the number of targets, the spacing of targets within the group, round trajectories for followers, which target it is engaging, the round's position relative to members of the group, its current altitude, and the like. This information is transmitted via a communication link 130 such as an EO/IR transmitter to one or more follower rounds (see, FIG. 7B).

Referring to FIG. 7B, a follower round 150 receives data from a forward round (see, FIG. 7A) via a SAL seeker 152. The seeker 152 decodes a communications message and determines the Az/El of the other rounds in its FOV. The follower round 150 also has an imager 154 and additional components 156 much like the leading round. The on-board processor 158 adds the round's data to the received data to complete the cascade by transmitting the combined data 162 via a communications link 160 to other following rounds and performs all other lead functions as needed. Some of the additional components on the leader round are not shown on the follower round, for simplicity.

Referring to FIG. 8, a diagram of another embodiment of swarm navigation using an augmented low cost semi-active laser for altimeter and command detonation functions according to the principles of the present disclosure is shown. More particularly, using the low cost semi-active laser seeker in the stowed position, augmented with a high power laser diode, can determine where the ground 200 is at some altitude such as between 0 and 3000 meters. This immediately determines if a shot is “high level” 202 or “low level” 204. A high level or high altitude engagement can be determined by the absence of a return pulse detected at the round by the laser altimeter as well as very low single to noise. A low altitude engagement can be determined by the detection of a return pulse by the laser altimeter on the round and reasonable signal to noise. Coupled with a barometer, for example, the system can then track the altitude of the round. In the forward looking position, the augmented low cost semi-active laser can provide a command detonation feature for air or potential ground targets—personnel vs vehicles.

Referring to FIG. 9, one embodiment of a method according to the present disclosure is shown. More specifically, the method provides a plurality of rounds, wherein the plurality of rounds comprises a leader round and one or more follower rounds. An optional step includes a designator painting a target area such that the SAL seeker on at least the leader round is guided to the target area. Referring again to FIG. 9, pulsed energy is generated, via a diode, to illuminate a target area comprising one or more targets 300. In one example, the diode provides for a laser range finder altimeter function 302. In a further example, the diode provides a proximity sensor for determining range to the target area comprising the targets 304 allowing the round to detonate. In yet a further example, the diode provides for 3D LIDAR processing 306 for target aim refinement by combining data from a SAL seeker imager, wherein the SAL seeker has 1-2 mrad spatial resolution. Pulsed energy from the diode is reflected from the target area and is received via the SAL seeker 308, and angular bearing information is determined 310. A receiver function is provided via an optical communications link for messages from the leader rounds 312. A horizon is used to determine an up and down reference via an imager having a FOV 314. Images of the target area are collected via the imager 316 and images of targets are captured within the target area, via the imager 318. A processor correlates received pulsed energy reflected from the target area via the SAL seeker with images of the scene captured by the imager to form 3D images of the targets within the target area 320. A data set is determined 322 and transmitted to remaining rounds in via a communication link 324.

The computer readable medium as described herein can be a data storage device, or unit such as a magnetic disk, magneto-optical disk, an optical disk, or a flash drive. Further, it will be appreciated that the term “memory” herein is intended to include various types of suitable data storage media, whether permanent or temporary, such as transitory electronic memories, non-transitory computer-readable medium and/or computer-writable medium.

It will be appreciated from the above that the invention may be implemented as computer software, which may be supplied on a storage medium or via a transmission medium such as a local-area network or a wide-area network, such as the Internet. It is to be further understood that, because some of the constituent system components and method steps depicted in the accompanying Figures can be implemented in software, the actual connections between the systems components (or the process steps) may differ depending upon the manner in which the present invention is programmed. Given the teachings of the present invention provided herein, one of ordinary skill in the related art will be able to contemplate these and similar implementations or configurations of the present invention.

It is to be understood that the present invention can be implemented in various forms of hardware, software, firmware, special purpose processes, or a combination thereof. In one embodiment, the present invention can be implemented in software as an application program tangible embodied on a computer readable program storage device. The application program can be uploaded to, and executed by, a machine comprising any suitable architecture.

While various embodiments of the present invention have been described in detail, it is apparent that various modifications and alterations of those embodiments will occur to and be readily apparent to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the appended claims. Further, the invention(s) described herein is capable of other embodiments and of being practiced or of being carried out in various other related ways. In addition, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having,” and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items while only the terms “consisting of” and “consisting only of” are to be construed in a limitative sense.

The foregoing description of the embodiments of the present disclosure has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It is intended that the scope of the present disclosure be limited not by this detailed description, but rather by the claims appended hereto.

A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the scope of the disclosure. Although operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.

While the principles of the disclosure have been described herein, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation as to the scope of the disclosure. Other embodiments are contemplated within the scope of the present disclosure in addition to the exemplary embodiments shown and described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present disclosure. 

What is claimed:
 1. A round, comprising: a forward facing diode configured to generate pulsed energy to illuminate a target area comprising one or more targets; provide a laser range finder altimeter function; provide a proximity sensor for determining range to the target area; and provide for 3D LIDAR processing for target aim refinement by combing data from a SAL seeker; the SAL seeker configured to receive the pulsed energy reflected from the target area; an imager having a field of view (FOV), the imager being configured to collect images of the target area; a processor configured to correlate data of the received pulsed energy reflected from the target area via the SAL seeker with the images of the scene captured by the imager and generate a target data set; and a rearward facing optical transmitter for sending the target data set to one or more follower rounds.
 2. The round according to claim 1, further comprising one or more navigation sensors and inertial measurement units (IMUs).
 3. The round according to claim 1, further comprising a barometer to indicate altitude once calibrated by the laser altimeter.
 4. The round according to claim 1, further comprising a deployment mechanism for deploying a sensor suite from a radial viewing mode to a forward looking mode for use as a proximity sensor during terminal guidance.
 5. The system for swarm navigation using a follow the forward approach according to claim 1, further comprising using 3D images from the correlated data for target ID and command detonation for a target type.
 6. The system for swarm navigation using a follow the forward approach according to claim 1, wherein the data set comprises one or more of: time from launch and estimated time to go to the target area; a number of targets in the target area; a spacing for multiple targets within the target area; a target cross range dispersion; a range from the round to the multiple targets in the target area; the round's position relative to remaining plurality of rounds; the round's current altitude; which target the leader round is engaging; and a selected target based on the round's control authority and its range or time to go to the selected target, after removing previously selected targets (if the round is a follower) from the total targets in the target area.
 7. A method for swarm navigation, comprising: providing a plurality of rounds, wherein the plurality of rounds comprises a leader round and one or more follower rounds, the rounds comprising: generating pulsed energy, via a diode, to illuminate a target area comprising one or more targets; receiving pulsed energy reflected from the target area, via the SAL seeker; determining angular bearing information, via the SAL seeker, of a leader round; using a horizon to determine an up and down reference via an imager having a FOV; capturing images of the target area, via an imager; correlating data of the received pulsed energy reflected from the target area via the SAL seeker with images of the scene captured by the imager to determine a target data set, via a processor; providing an optical communications link for messages from a leader round to one or more follower rounds; transmitting the data set to the one or more follower rounds via a communication link.
 8. The method for swarm navigation according to claim 7, further comprising providing additional components including one or more navigation sensors, and IMUs.
 9. The method for swarm navigation according to claim 7, further comprising providing a barometer to maintain altitude once calibrated by the laser altimeter.
 10. The method for swarm navigation according to claim 7, further comprising deploying the sensor suite from a radial viewing mode to a forward looking mode for use as a proximity sensor during terminal guidance.
 11. The method for swarm navigation according to claim 7, further comprising using the correlated data for 3D images for use in target ID and command detonation for a target type.
 12. The method for swarm navigation according to claim 7, further comprising using a designator.
 13. A method for swarm navigation, comprising: providing a plurality of rounds, wherein the plurality of rounds comprises a leader round and one or more follower rounds, each round comprising: generating pulsed energy, via a diode, to illuminate a target area comprising multiple targets; providing a transmitter portion of a laser range finder altimeter function, via the diode; providing a transmitter portion of a proximity sensor, via the diode, for determining range to the target area comprising multiple targets; providing a transmitter portion for a 3D LIDAR function, via the diode, for target aim refinement by combing data from a SAL seeker imager; receiving pulsed energy reflected from the target area, via the SAL seeker; determining angular bearing information, via the SAL seeker, if a follower round of any rounds in front of it; providing a receiver function via an optical communications link for messages from the plurality of rounds; using a horizon to determine an up and down reference via an imager having a FOV; collecting images of the target area, via the imager; capturing images of multiple targets within the target area, via the imager; correlating received pulsed energy reflected from the target area via the SAL seeker with images of the scene captured by the imager to form 3D images of multiple targets within the target area, via a processor; determining, via the processor, a data set; and transmitting the data set to remaining rounds in the plurality of rounds via a communication link.
 14. The method according to claim 13, wherein the data set comprises: a time from launch and estimated time to go to the target area; a number of targets in the target area; a spacing for multiple targets within the target area; a target cross range dispersion; a range from the round to the multiple targets in the target area; the round's position relative to remaining plurality of rounds; the round's current altitude; which target the leader round is engaging; and a selected target based on the round's control authority and its range or time to go to the selected target, after removing previously selected targets (if the round is a follower) from the total targets in the target area.
 15. The method according to claim 13, further comprising providing additional components including one or more navigation sensors, and IMUs.
 16. The method according to claim 13, further comprising providing a barometer to maintain altitude once calibrated by the laser altimeter.
 17. The method according to claim 13, further comprising deploying the sensor suite from a radial viewing mode to a forward looking mode for use as a proximity sensor during terminal guidance.
 18. The method according to claim 13, further comprising using correlated data for 3D images for use in target ID and command detonation for a target type.
 19. The method according to claim 13, wherein the SAL seeker has 1-2 mrad spatial resolution.
 20. The method of swarm navigation according to claim 7, wherein the data set comprises: a time from launch and estimated time to go to the target area; a number of targets in the target area; a spacing for multiple targets within the target area; a target cross range dispersion; a range from the round to the multiple targets in the target area; the round's position relative to remaining plurality of rounds; the round's current altitude; which target the leader round is engaging; and a selected target based on the round's control authority and its range or time to go to the selected target, after removing previously selected targets (if the round is a follower) from the total targets in the target area. 